Brush assembly of cleaner

ABSTRACT

A brush assembly of a cleaner includes a driving motor mounted at a cleaner main body, for generating a rotary force; a brush rotatably disposed at a suction opening formed at the cleaner main body; and a driving force transfer device installed between the driving motor and the brush, rotating the brush by transferring a rotary force of the driving motor to the brush, and protecting the driving motor by preventing transfer of a load generated at the brush to the driving motor. Accordingly, the driving motor can be continuously rotated even if the brush cannot be rotated by being caught by a stuff or the like, thereby preventing motor damage.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a brush assembly of a cleaner, andparticularly, to a brush assembly of a cleaner capable of preventingmotor damage by keeping the motor rotating when a brush cannot berotated by being caught by a stuff or the like.

2. Description of the Background Art

In general, a robot cleaner performs a cleaning operation while movingfor itself without manipulation of a user, moves to a charging stationif power of a battery is consumed during cleaning, and moves back to acleaning zone to perform a cleaning operation when the battery charge iscompleted.

A brush assembly for sweeping up dirt or foreign substances from a flooris installed at a suction opening through which dirt is sucked, of therobot cleaner.

FIG. 1 is a side view showing a brush assembly of a robot cleaner inaccordance with the conventional art.

The brush assembly in accordance with the conventional art includes adriving motor 102 for generating a rotary force; a brush 106 rotatablyinstalled at a suction opening of the robot cleaner, for sweeping updirt and foreign substances from a floor; and a driving force transferdevice 120 for transferring a rotary force of the driving motor 102 tothe brush 106.

Here, the driving force transfer device 120 includes a driving pulley108 mounted at a rotary shaft 104 of the driving motor 102; a drivenpulley 110 mounted at a rotary shaft 116 of the brush 106; and a belt112 wound between the driving pulley 108 an the driven pulley 110 totransfer a driving force.

In another embodiment, the driving force transfer device includes adriving gear mounted at the rotary shaft of the driving motor; and adriven gear mounted at the rotary shaft of the brush, and transfers adriving force as the driving gear and the driven gear are engaged witheach other.

However, because the brush driving force transfer device in accordancewith the conventional art mechanically transfers a rotary force of thedriving motor to the brush, a motor overload occurs as the brush cannotbe rotated by being caught by a stuff or the like, causing motor damage.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a brushassembly of a cleaner capable of preventing motor damage by normallyrotating a driving motor when a brush cannot be rotated by being caughtby a stuff or the like.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a brush assembly of a cleaner comprising: a drivingmotor mounted at a cleaner main body, for generating a rotary force; abrush rotatably disposed at a suction opening formed at the cleaner mainbody; and a driving force transfer device installed between the drivingmotor and the brush, rotating the brush by transferring a rotary forceof the driving motor to the brush, and protecting the driving motor bypreventing transfer of a load generated at the brush to the drivingmotor.

The driving force transfer device comprises: a first magnet mounted at arotary shaft of the driving motor; and a second magnet mounted at arotary shaft of the brush and disposed to face the first magnet so thatan attractive force can work between itself and the first magnet.

The attractive force working between the first magnet and the secondmagnet is set to be smaller than the rotary force of the driving motor.

The driving force transfer device comprises: a magnetic body mounted ata rotary shaft of the motor; and a magnet mounted at a rotary shaft ofthe brush and disposed to face the magnetic body.

The driving force transfer device comprises: a magnet mounted at arotary shaft of the driving motor; and a magnetic body mounted at arotary shaft of the brush and disposed to face the magnet.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a brush assembly of a robot cleaner provided with asuction opening at the center of a bottom of a cleaner main body,performing a cleaning operation while moving for itself, andautomatically charging a battery, comprising: a driving motor mounted atthe cleaner main body, for generating a rotary force; a brush rotatablydisposed at the suction opening; and a driving force transfer deviceinstalled between the driving motor and the brush, rotating the brush bytransferring the rotary force of the driving motor to the brush, andpreventing transfer of a load generated at the brush to the motor.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute aunit of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a side view showing a brush assembly of a cleaner inaccordance with the conventional art;

FIG. 2 is a front view of a cleaner in accordance with one embodiment ofthe present invention;

FIG. 3 is a rear view of the cleaner in accordance with one embodimentof the present invention;

FIG. 4 is a sectional view of the cleaner in accordance with oneembodiment of the present invention;

FIG. 5 is a perspective view of a brush assembly of the cleaner inaccordance with one embodiment of the present invention;

FIG. 6 is a side view of the brush assembly of the cleaner in accordancewith one embodiment of the present invention; and

FIGS. 7 and 8 are views showing operation of the brush assembly of thecleaner in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

A plurality of embodiments of a brush assembly of a cleaner inaccordance with the present invention may exist, and the most embodimentwill be described.

FIG. 2 is a side view of a robot cleaner in accordance with oneembodiment of the present invention, FIG. 3 is a rear view of the robotcleaner in accordance with one embodiment of the present invention, andFIG. 4 is a sectional view of the robot cleaner in accordance with oneembodiment of the present invention.

The robot cleaner in accordance with the present invention includes: acleaner main body 10; a suction fan 12 mounted in the cleaner main body10, for generating a suction force of the cleaner; a filter container 16mounted in front of the suction fan 12 and having therein a filter 14for collecting dirt or filth sucked by the suction fan 12; a suctionopening 20 connected to the filter container 16 through a suction pipe18 and formed at a lower side of the main body 10 to suck dirt or filthon a floor 30; and a brush assembly 22 rotatably mounted at one side ofthe suction opening 20, for sweeping up the dirt and filth from thefloor 30.

An ultrasonic wave transmitter 24 for transmitting ultrasonic waves whenthe cleaner main body 10 moves, and an ultrasonic wave receiver 26 forreceiving the ultrasonic waves transmitted from the ultrasonic wavetransmitter 24 are mounted at the front of the cleaner main body 10 todetect a position of an obstacle.

A charging terminal 28 is mounted at a rear of the cleaner main body 10,and a battery 32 is charged as the charging terminal 28 is connected toa connection terminal 42 installed on a wall 40 of a room. In addition,a light emitting unit 34 for inducing the charging terminal 28 to theconnection terminal 42 is installed at the rear of the cleaner main body10, and a light receiving unit 44 for receiving an optical signalemitted from the light emitting unit 34 is installed on the wall 40 ofthe room, where the connection terminal 42 is installed.

A pair of driving wheels 38 driven by a motor 36, and auxiliary wheels48 supporting the cleaner main body 10 and maintaining a horizontalstate are mounted at a lower side of the cleaner main body 10.

FIG. 5 is a perspective view of a brush assembly in accordance with oneembodiment of the present invention, and FIG. 6 is a side view of thebrush assembly in accordance with one embodiment of the presentinvention.

The brush assembly 22 includes: a driving motor 50 mounted at the mainbody 10, for generating a rotary force; a brush 52 rotatably disposed atthe suction opening 20; and a driving force transfer device 58 installedbetween a rotary shaft 54 of the driving motor 50 and a rotary shaft 56of the brush 52 to transfer a rotary force of the driving motor 50 tothe brush 52, and protecting the driving motor 50 by preventing a loadgenerated at the brush 52, for example, as the brush 52 is caught by astuff, from being transferred to the driving motor 50.

The driving force transfer device 58 includes a first magnet 60 mountedat a rotary shaft 54 of the driving motor 50 to be rotated therewith;and a second magnet 62 mounted at a rotary shaft 56 of the brush 52 anddisposed to face the first magnet 60, so that an attractive force worksbetween the first magnet 60 and the second magnet 62.

Here, each of the first magnet 60 and the second magnet 62 is formed asa disc shape, and the attractive force working between the first magnet60 and the second magnet 62 is set to be smaller than a rotary force ofthe driving motor 50.

And, surfaces of the first magnet 60 and the second magnet 62, whichface each other, have opposite polarities, so that an attractive forcecan work between the first magnet 60 and the second magnet 62. Namely,as one embodiment, if a facing surface of the first magnet 60 has anorth (N) pole, a facing surface of the second magnet 62 has a south (S)pole.

In another embodiment, the driving force transfer device includes amagnetic body (not shown) mounted at the rotary shaft 54 of the drivingmotor 50; and a magnet (not shown) mounted at the rotary shaft 56 of thebrush 52 and disposed to face the magnetic body. Therefore, a rotaryforce of the driving motor 50 is transferred to the brush 52 by anattractive force working between the magnetic body and the magnet. If aload is generated, for example, as the brush 52 is caught by a stuff, amagnetism of the magnet is overcome, and only the magnetic body isrotated, thereby preventing transfer of the load generated at the brushto the driving motor 50.

In still another embodiment of the driving force transfer device, amagnet (not shown) is mounted at the rotary shaft 54 of the drivingmotor 50, and a magnetic body (not sown) is mounted at the rotary shaft56 of the brush 52, wherein the magnet and the magnetic body aredisposed to face each other.

Operation of the cleaner in accordance with present invention will nowbe described.

FIGS. 7 and 8 are views showing the operation of the brush assembly ofthe cleaner in accordance with the present invention.

When a user presses an operation button, power of a battery 32 istransmitted to the suction fan 12, and the suction fan 12 is driven.Then, a suction force is generated by the driving of the suction fan 12,and thus dirt or filth on the floor 30 are sucked to the suction opening20 and collected in the filter 14 through the suction pipe 18.

At this time, the brush is rotated 52, sweeping up the dirt and filthfrom the floor into the suction opening 20. Namely, a rotary force ofthe driving motor 50 is transferred to the brush 52 through the drivingforce transfer device 58, thereby rotating the brush 52.

The operation of the driving force transfer device 58 will now bedescribed. First, as shown in FIG. 7, when the driving motor 50 isdriven, the first magnet 60 mounted at the rotary shaft 54 of thedriving motor 50 is rotated, and the second magnet 62 positioned to facethe first magnet 60 is rotated by an attractive force working betweenitself and the first magnet 60, thereby rotating the second brush 52connected to the second magnet 62.

As shown in FIG. 8, even if the brush 52 cannot be rotated as a stuff 70or the like is undesirably put between the brush 52 and the suctionopening 20 during a cleaning operation, the driving motor 50 iscontinuously and normally rotated because the rotary force of thedriving motor 50 is greater than the attractive force working betweenthe first magnet 60 and the second magnet 62. Accordingly, the drivingmotor damage due to an overload can be prevented.

In the brush assembly of the cleaner constructed and operated in such amanner, the first magnet and the second magnet are disposed between thedriving motor and the brush in a facing manner, and a rotary force ofthe driving motor is transferred to the brush by an attractive forceworking between the first magnet and the second magnet, so that thedriving motor is normally rotated even if rotation of the brush isstopped as the brush is caught by a stuff or the like. Accordingly, thedriving motor can be prevented from being damaged by an overload.

In addition, because the brush is driven only by a force correspondingto an attractive force working between the first magnet and the secondmagnet, if friction severely occurs between the brush and the floor, thebrush stops rotating, thereby preventing floor damage.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are therefore intendedto be embraced by the appended claims.

1. A brush assembly of a cleaner comprising: a driving motor mounted ata cleaner main body, for generating a rotary force; a brush rotatablydisposed at a suction opening formed at the cleaner main body; and adriving force transfer device installed between the driving motor andthe brush, rotating the brush by transferring a rotary force of thedriving motor to the brush, and protecting the driving motor bypreventing transfer of a load generated at the brush to the drivingmotor.
 2. The brush assembly of claim 1, wherein the driving forcetransfer device comprises: a first magnet mounted at a rotary shaft ofthe driving motor; and a second magnet mounted at a rotary shaft of thebrush and disposed to face the first magnet so that an attractive forcecan work between itself and the first magnet.
 3. The brush assembly ofclaim 2, wherein the attractive force working between the first magnetand the second magnet is set to be smaller than the rotary force of thedriving motor.
 4. The brush assembly of claim 1, wherein the drivingforce transfer device comprises: a magnetic body mounted at a rotaryshaft of the motor; and a magnet mounted at a rotary shaft of the brushand disposed to face the magnetic body.
 5. The brush assembly of claim4, wherein an attractive force working between the magnetic body and themagnet is set to be smaller than the rotary force of the driving motor.6. The brush assembly of claim 1, wherein the driving force transferdevice comprises: a magnet mounted at a rotary shaft of the drivingmotor; and a magnetic body mounted at a rotary shaft of the brush anddisposed to face the magnet.
 7. A brush assembly of a robot cleanerprovided with a suction opening at the center of a bottom of a cleanermain body, performing a cleaning operation while moving for itself, andautomatically charging a battery, comprising: a driving motor mounted atthe cleaner main body, for generating a rotary force; a brush rotatablydisposed at the suction opening; and a driving force transfer deviceinstalled between the driving motor and the brush, rotating the brush bytransferring the rotary force of the driving motor to the brush, andpreventing transfer of a load generated at the brush to the motor. 8.The brush assembly of claim 7, wherein the driving force transfer devicecomprises: a first magnet mounted at a rotary shaft of the drivingmotor; and a second magnet mounted at a rotary shaft of the brush anddisposed to face the first magnet so that an attractive force can workbetween itself and the first magnet.
 9. The brush assembly of claim 8,wherein the attractive force working between the first magnet and thesecond magnet is set to be smaller than the rotary force of the drivingmotor.
 10. The brush assembly of claim 7, wherein the driving forcetransfer device comprises: a magnetic body mounted at a rotary shaft ofthe motor; and a magnet mounted at a rotary shaft of the brush anddisposed to face the magnetic body.
 11. The brush assembly of claim 10,wherein the attractive force working between the magnetic body and themagnet is set to be smaller than the rotary force of the driving motor.12. The brush assembly of claim 7, the driving force transfer devicecomprises: a magnet mounted at a rotary shaft of the driving motor; anda magnetic body mounted at a rotary shaft of the brush and disposed toface the magnet.